Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Surface Profile with Position of point? (ISO GPS)

Surface Profile with Position of point? (ISO GPS)

Surface Profile with Position of point? (ISO GPS)

Dear all,

I am trying to control the main outside profile of this part but hold the end feature to a tighter tolerance.
See attached: https://files.engineering.com/getfile.aspx?folder=...

Is this an acceptable use of the surface profile call out with a specific feature using the size/TP call out?
I am working on BS8888 - ISO GPS, and provide 3D CAD models to our supplier.

This part rotates on the 5mm hole and is intended to locate another part preciecly on the 2mm nub.

Additionally, would this be an achievable tolerance of a part on a CNC machine?


RE: Surface Profile with Position of point? (ISO GPS)

Just to clarify:
I think position can be used as refinement of the all around profile. Again, I think is clear. However I am not sure if it is legal, but I think so.

My previous issues (copy-paste below) is about collection plane indicator and its mandatory usage. I think you have to use it per the latest ISO standards.

The question I have is: do you have to use collection plane indicator?

Per ISO1101/2017 paragraph 16.1
Collection planes shall be used when the “all around” symbol is applied. The collection plane identifies a family of parallel planes, which identifies the features covered by the “all around” indication.

Per paragraph 9 we can read:
If a geometrical specification is applied to the outlines of the cross-sections or if it is applied to all features represented by a closed outline, it shall be indicated by the symbol “all around” placed on the intersection of the leader line and the reference line of the tolerance indicator (see examples Figure 51 and 53). A collection plane indicator shall be used to identify the collection plane in 3D and is preferred in 2D. For deprecated 2D practice, see A.2.3. An all around requirement applies only to the surfaces identified by the collection plane, not to the entire workpiece (see Figure 52 and 54).

RE: Surface Profile with Position of point? (ISO GPS)

Anyone else?
Any other opinions?

RE: Surface Profile with Position of point? (ISO GPS)

Thanks Greenimi,

Thanks for pointing out the requirement of collection planes! I thought it was somewhat implied from the view, but I see it must be defined.
And on second thoughts I think the Line Pofile may be a sufficient call out for my application.
Is there a way to define at which hieght the line profile should be taken, or our multiple highets usually taken?

If anyone else can confirm the legality of using true position for refining the surface profile that would be great.


RE: Surface Profile with Position of point? (ISO GPS)

Quote (OP)

And on second thoughts I think the Line Pofile may be a sufficient call out for my application.

I would use surface profile and not line profile

Regarding you second question, I would say that by line profile definition you have to take each and every height, but there is "no connection" between those measurements (no simultaneous requirement since you don't have a complete datum system |A|B|C| and also you don't have CZ or SIM's indicators)

On a different thread pmarc said "would be no difference between line profile and surface profile in the |A|B|C| case."



Am I on the right track here? What do you think?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close